Improvement in surgical splints



UNITED STATES PATENT OFFICE.

JOHN E. JOHNSON, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN SURGICAL SPLINTS.

Specification forming part of Letters Patent No. 216,680, dated June 17,1879; application filed I February 27, 1879.

To all whom "it may concern:

Be it known that 1, JOHN E. JoHNsoN, of the city and county ofPhiladelphia, State of Pennsylvania, have invented a new and usefulImprovement in Surgical Splints, of which the following is aspecification.

My invention relates to that class of splints which are constructed of apliable material,

' stiffened with gums, and molded to the deas those mentioned in thesaid patents of David .Ahl, omitting, however, the acid bath referred toin Patent N 0. 23,996.

My improvement over the Ahl splints consists in the particularconstruction of the fabric, and in the manipulation thereof at the timeof the application of the stiffening solution, whereby signal advantageis gained over the Ahl splint in that there are secured a greater degreeof porosity and cleaner exterior surfaces, whereby they are madecomparatively free from the stiffening-gums, and, consequently, muchsofter to the touch than are the surfaces of splints made according tothe modes described by David Ahl in his'said Letters Patent.

My method of making my improved splints is as follows: I form the fabricof alternate layers (three or more) of live or long-staple wool, and ofshort stock, composed of wool, cotton, or a mixture of wool and cotton,or other suitable materials.

I have found in practice that five layers produce the best results; butwhatever number may be used they should be so disposed that the outerlayers shall be of the long-staple fiber.

The whole must be well felted together in the usual way. The feltedcloth is then stiffened by the application of a solution of shellac orother substance adapted for the purpose, as mentioned in Ahls saidpatents; but instead of smoothing the material with a hot iron for thepurpose of concentrating the gum, as is done by Ahl, as stated in hisLetters Patent N 0. 33,470, I run the felted sheet betweencalender-rollers, or equivalent mechanical devices, under pressure, inorder to equalize the distribution of the stiffening-solution and tosimultaneously force the latter through the exterior layers in towardthe medial partof the fabric. The result is that when the latter, as itpasses from between the rollers and is thereupon relieved fromcompression, expands, it draws the solution to the fibers, thus breakingup the continuity of the gummy liquid and rendering the fabric penfectly porous after being dried. This porosity it retains indefinitely.

The stuff may afterward be molded into the specific conformationsdesired by heat, steam or radiated heat being preferable.

The lack of external softness, combined with internal rigidity, and,more especially, the practical absence of porosity, are the strikingobjectional features of splints manufactured according to thespecifications of David Ahls said patents.

Ahls method of concentrating the gums by means of a hot iron causes thescattered particles thereof to coalesce and fill up the intersticeswhich would otherwise, to some extent, exist between the fibers of thefelted fabric. This defect is recognized and attempted to be remedied byAhl in the specification of his Letters Patent of October 15, 1861, No.33,470, wherein he states that the splints may be perforated torenderthem porous.

Besides those hereinbeforementioned, my improved surgical splints retainall the advan tages of the Ahl splint, as set forth at length in hissaid patents, to which reference may be had.

Having thus described my invention, what I claim as new, and wish tosecure by Letters Patent, is-

1. A felted fabric for surgical splints, composed of alternate layers oflong staple and of short stock,"and treated with a stiffening-solu- 3.As a new article of manufacture, surgical tion, substantially as and forthe purposes desplints constructed of the fabric made and scribed.treated as described.

2. The method or process of preparing such In witness whereof I havehereunto set my fabric, as hereinbefore described, by passing hand this26th day of February, A. D. 1879.

the same when saturated with a stiffening-so- JOHN E. JOHNSON. lutionbetween rollers under pressure, whereby In presence ofporosity andexternal softness of the fabric are JOHN RUSSELL,

. retained, as set forth. GEORGE fiUssELL.

